Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028296
A. Adamopoulos, P. Anninos, S. Likothanassis, G. Beligiannis, L. Skarlas, E. N. Demiris, D. Papadopoulos
A novel technique for the analysis, nonlinear model identification and prediction of the fetal magnetocardiogram (f-MCG) is presented. f-MCGs can be recorded with the use of specific totally non-invasive superconductive quantum interference devices (SQUID). For the analysis and classification of the f-MCG signals we introduce an intelligent method that combines the following well known advanced signal processing techniques: the genetic algorithms (GA), the multimodel partitioning (MMP) theory and the extended Kalman filters (EKF). Simulations illustrate that the proposed method is selecting the correct model structure and identifies the model parameters in a sufficiently small number of iterations and tracks successfully changes in the signal, in real time. The information provided by the proposed analysis is easily interpreted and assessed by gynecologists and consist of the clinical status of the fetus. The proposed algorithm can be parallel implemented and also a VLSI implementation is feasible.
{"title":"Evolutionary self-adaptive multimodel prediction algorithms of the fetal magnetocardiogram","authors":"A. Adamopoulos, P. Anninos, S. Likothanassis, G. Beligiannis, L. Skarlas, E. N. Demiris, D. Papadopoulos","doi":"10.1109/ICDSP.2002.1028296","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028296","url":null,"abstract":"A novel technique for the analysis, nonlinear model identification and prediction of the fetal magnetocardiogram (f-MCG) is presented. f-MCGs can be recorded with the use of specific totally non-invasive superconductive quantum interference devices (SQUID). For the analysis and classification of the f-MCG signals we introduce an intelligent method that combines the following well known advanced signal processing techniques: the genetic algorithms (GA), the multimodel partitioning (MMP) theory and the extended Kalman filters (EKF). Simulations illustrate that the proposed method is selecting the correct model structure and identifies the model parameters in a sufficiently small number of iterations and tracks successfully changes in the signal, in real time. The information provided by the proposed analysis is easily interpreted and assessed by gynecologists and consist of the clinical status of the fetus. The proposed algorithm can be parallel implemented and also a VLSI implementation is feasible.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116731478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028231
H. Berndt, H. Jentschel
Scalar signal quantization is commonly based on a deterministic definition of nonlinear transfer functions. However, in the more general case of stochastic quantization a non-deterministic approach is required. This paper presents an analysis of general stochastic quantization properties derived from a model incorporating a regular deterministic quantizer. It is shown how stochastic quantization transfer functions providing constant mean square error independent of the actual probability density distribution of the signal being quantized can be derived. Simulation results illustrating performance and limits of the proposed quantizer are given.
{"title":"Stochastic quantization transfer functions for high resolution signal estimation","authors":"H. Berndt, H. Jentschel","doi":"10.1109/ICDSP.2002.1028231","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028231","url":null,"abstract":"Scalar signal quantization is commonly based on a deterministic definition of nonlinear transfer functions. However, in the more general case of stochastic quantization a non-deterministic approach is required. This paper presents an analysis of general stochastic quantization properties derived from a model incorporating a regular deterministic quantizer. It is shown how stochastic quantization transfer functions providing constant mean square error independent of the actual probability density distribution of the signal being quantized can be derived. Simulation results illustrating performance and limits of the proposed quantizer are given.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126691647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028323
K. Valasoulis, D. Fotiadis, I. Lagaris, A. Likas
Artificial neural networks have been successfully employed for the solution of ordinary and partial differential equations. According to this methodology, the solution to a differential equation is written as a sum of two parts. The first part satisfies the initial/boundary conditions and contains no adjustable parameters. The second part involves a feedforward neural network (MLP) whose weights must be adjusted in order to solve the equation. A significant advantage of the above methodology is the ability of of direct hardware implementation of both the solution and the training procedure. In this work we describe the implementation of the method on a hardware platform with two digital signal processors. We address several implementation and performance issues and provide comparative results against a PC-based implementation of the method.
{"title":"Solving differential equations with neural networks: implementation on a DSP platform","authors":"K. Valasoulis, D. Fotiadis, I. Lagaris, A. Likas","doi":"10.1109/ICDSP.2002.1028323","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028323","url":null,"abstract":"Artificial neural networks have been successfully employed for the solution of ordinary and partial differential equations. According to this methodology, the solution to a differential equation is written as a sum of two parts. The first part satisfies the initial/boundary conditions and contains no adjustable parameters. The second part involves a feedforward neural network (MLP) whose weights must be adjusted in order to solve the equation. A significant advantage of the above methodology is the ability of of direct hardware implementation of both the solution and the training procedure. In this work we describe the implementation of the method on a hardware platform with two digital signal processors. We address several implementation and performance issues and provide comparative results against a PC-based implementation of the method.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130598487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028337
I. P. Mariño, L. López, J. Míguez, M. Sanjuán
One of the most outstanding properties of chaotic dynamical systems is their extreme sensitivity to small perturbations. Far from being a disadvantage, this feature can be exploited to devise a simple technique that allows to control the symbolic dynamics of a chaotic system by applying small perturbations to the system trajectory. In this paper, we show how this procedure can be employed to differentially encode an arbitrary binary message within a continuous-time chaotic waveform generated by a chaotic system. This chaotic waveform is an information-bearing signal that naturally presents a high degree of redundancy. By exploiting this property, we introduce a novel chaotic channel code with error-correcting capabilities.
{"title":"A novel channel coding scheme based on continuous-time chaotic dynamics","authors":"I. P. Mariño, L. López, J. Míguez, M. Sanjuán","doi":"10.1109/ICDSP.2002.1028337","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028337","url":null,"abstract":"One of the most outstanding properties of chaotic dynamical systems is their extreme sensitivity to small perturbations. Far from being a disadvantage, this feature can be exploited to devise a simple technique that allows to control the symbolic dynamics of a chaotic system by applying small perturbations to the system trajectory. In this paper, we show how this procedure can be employed to differentially encode an arbitrary binary message within a continuous-time chaotic waveform generated by a chaotic system. This chaotic waveform is an information-bearing signal that naturally presents a high degree of redundancy. By exploiting this property, we introduce a novel chaotic channel code with error-correcting capabilities.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"456 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123647045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028282
S. Makrogiannis, G. Economou, S. Fotopoulos
An inter-region color dissimilarity measure is proposed that utilizes the basic principles of region based segmentation and fuzzy clustering techniques. This method operates on the features associated to the initial image partitioning produced by watershed analysis. The subtractive clustering algorithm is employed to estimate the number of clusters and the fuzzy c-means classification method follows. The membership values assigned to each region along with a fuzzy (dis)similarity measure are used to estimate the cost between the regions. The process is completed using the shortest spanning tree merging algorithm. The proposed method is also compared to other related approaches.
{"title":"A fuzzy region dissimilarity measure using feature space information","authors":"S. Makrogiannis, G. Economou, S. Fotopoulos","doi":"10.1109/ICDSP.2002.1028282","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028282","url":null,"abstract":"An inter-region color dissimilarity measure is proposed that utilizes the basic principles of region based segmentation and fuzzy clustering techniques. This method operates on the features associated to the initial image partitioning produced by watershed analysis. The subtractive clustering algorithm is employed to estimate the number of clusters and the fuzzy c-means classification method follows. The membership values assigned to each region along with a fuzzy (dis)similarity measure are used to estimate the cost between the regions. The process is completed using the shortest spanning tree merging algorithm. The proposed method is also compared to other related approaches.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127682686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028146
G. Anastassopoulos, A. D. Tsalkidis, I. Stephanakis, G. Mandellos, K. Simopoulos
A medical database has been developed in the pediatric clinic of the University Hospital of Alexandroupolis in order to organize and manipulate all clinical information in digital form. A compression technique that trades between the amount of data stored/transmitted and the quality of the image may be used in order to reduce the amount of stored/transmitted image data. A comparative evaluation of JPEG and JPEG2000 compression standards by means of both subjective and objective criteria was performed in order to select the appropriate compression technique for the database medical images. JPEG 2000 proves to be an ideal file format for the pediatric DB application, since it compresses the image data up to 98.4% without any loss in the diagnostic information of the image.
{"title":"Application of JPEG 2000 compression in medical database image data","authors":"G. Anastassopoulos, A. D. Tsalkidis, I. Stephanakis, G. Mandellos, K. Simopoulos","doi":"10.1109/ICDSP.2002.1028146","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028146","url":null,"abstract":"A medical database has been developed in the pediatric clinic of the University Hospital of Alexandroupolis in order to organize and manipulate all clinical information in digital form. A compression technique that trades between the amount of data stored/transmitted and the quality of the image may be used in order to reduce the amount of stored/transmitted image data. A comparative evaluation of JPEG and JPEG2000 compression standards by means of both subjective and objective criteria was performed in order to select the appropriate compression technique for the database medical images. JPEG 2000 proves to be an ideal file format for the pediatric DB application, since it compresses the image data up to 98.4% without any loss in the diagnostic information of the image.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128170233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028242
L. Capdiferro, V. Casieri, A. Laurenti, G. Jacovitti
A novel technique for image enhancement based on a multiscale pyramid is presented. It generalizes the classical edge-oriented wavelet based enhancement technique by employing multiple wavelet features. Visually relevant features are amplified in the wavelet domain according to a pointwise multiscale product. The use of complex in-phase/quadrature wavelets allows features, which are oriented any way, to be emphasized.
{"title":"Multiple feature based multiscale image enhancement","authors":"L. Capdiferro, V. Casieri, A. Laurenti, G. Jacovitti","doi":"10.1109/ICDSP.2002.1028242","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028242","url":null,"abstract":"A novel technique for image enhancement based on a multiscale pyramid is presented. It generalizes the classical edge-oriented wavelet based enhancement technique by employing multiple wavelet features. Visually relevant features are amplified in the wavelet domain according to a pointwise multiscale product. The use of complex in-phase/quadrature wavelets allows features, which are oriented any way, to be emphasized.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"293 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132373428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028190
V. Fotopoulos, A. Skodras
In the paper, the effects of the imminent JPEG2000 compression standard on watermarking techniques are investigated. It is shown that the choice of different coding parameters affects the performance of transform domain watermarking techniques. Compression ratio is of course important but not the only parameter that a watermarking scheme should take into account.
{"title":"JPEG2000 parameters against watermarking","authors":"V. Fotopoulos, A. Skodras","doi":"10.1109/ICDSP.2002.1028190","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028190","url":null,"abstract":"In the paper, the effects of the imminent JPEG2000 compression standard on watermarking techniques are investigated. It is shown that the choice of different coding parameters affects the performance of transform domain watermarking techniques. Compression ratio is of course important but not the only parameter that a watermarking scheme should take into account.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134518183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028152
T. Sappasitwong, S. Aramvith, S. Jitapunkul, A. Tamtrakarn, P. Kitti-punyangam, H. Kortrakulkij
We present an adaptive asymmetric diamond search (AADS) for block based motion estimation. The proposed method exploits an adaptive search pattern based on the predicted motion vector. In addition, the accuracy of the prediction is improved by changing the initial search center position. Simulation results show that the proposed algorithm can reduce the number of search points by up to about 50% compared to the regular diamond search while keeping the picture quality similar to other fast search algorithms.
{"title":"Adaptive asymmetric diamond search algorithm for block-based motion estimation","authors":"T. Sappasitwong, S. Aramvith, S. Jitapunkul, A. Tamtrakarn, P. Kitti-punyangam, H. Kortrakulkij","doi":"10.1109/ICDSP.2002.1028152","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028152","url":null,"abstract":"We present an adaptive asymmetric diamond search (AADS) for block based motion estimation. The proposed method exploits an adaptive search pattern based on the predicted motion vector. In addition, the accuracy of the prediction is improved by changing the initial search center position. Simulation results show that the proposed algorithm can reduce the number of search points by up to about 50% compared to the regular diamond search while keeping the picture quality similar to other fast search algorithms.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134002290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-11-07DOI: 10.1109/ICDSP.2002.1028342
A. N. Kim, T. Ramstad
The optimal entropy constrained scalar quantizer (ECSQ) gives the best possible rate-distortion performance of any scalar quantizer. While at high bit rates the optimal ECSQ converges to the uniform quantizer, optimization at low-bit regions demands usually numerical solutions with high complexity. The performance of optimal ECSQ is compared with three simpler scalar quantization configurations: uniform threshold quantizer, uniform quantizer with Wiener filter and the zero input correlation quantizer with Wiener filter. Gaussian distributed inputs are used in the simulations. Results show that the simpler quantizers, are able to match the optimal ECSQ performance, even at low bit rates while the uniform quantizer with Wiener filter provides the simplest configuration.
{"title":"Comparing performance of entropy constrained scalar quantizer and other scalar quantizers","authors":"A. N. Kim, T. Ramstad","doi":"10.1109/ICDSP.2002.1028342","DOIUrl":"https://doi.org/10.1109/ICDSP.2002.1028342","url":null,"abstract":"The optimal entropy constrained scalar quantizer (ECSQ) gives the best possible rate-distortion performance of any scalar quantizer. While at high bit rates the optimal ECSQ converges to the uniform quantizer, optimization at low-bit regions demands usually numerical solutions with high complexity. The performance of optimal ECSQ is compared with three simpler scalar quantization configurations: uniform threshold quantizer, uniform quantizer with Wiener filter and the zero input correlation quantizer with Wiener filter. Gaussian distributed inputs are used in the simulations. Results show that the simpler quantizers, are able to match the optimal ECSQ performance, even at low bit rates while the uniform quantizer with Wiener filter provides the simplest configuration.","PeriodicalId":351073,"journal":{"name":"2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)","volume":"442 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134178966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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